Download 2-BuildingBlocks

Chapter 3:The Chemical
Building Blocks of Life
Topics you are not responsible for:
molar concentration
End of Chapter questions:
Understand: all
Apply: all
Synthesize: 1 & 3
Do all mQuiz questions
Chemical Building Blocks
1
What causes Alzheimer's disease?
Amyloid precursor protein is converted to β-Amyloid
APP is an integral membrane protein
Processing by ‘protease’-type enzymes (α-, β-, γ-secretase)
β-Amyloid  plaque formation
Many questions remain unanswered…
-- Do β-Amyloid plaques cause disease symptoms?
-- Why do some people get Alz Dis and other do not?
-- What are possible explanations?
Chemical Building Blocks
Amyloid
Plaques
AB42 > AB40
2
What are the fundamental properties
of organic molecules?
What are “organic” molecules?
What are hydrocarbons?
Molecular representations
Chemical Building Blocks
3
What “functional”
groups
occur on biological
molecules?
-- Know these like
“the back of your hand”!
e.g.
Cysteine
Chemical Building Blocks
4
What are the 4 major groups of macromolecules?
Proteins
Nucleic acids
Lipids
Carbohydrates
What are the molecular building
blocks (subunits) of each?
Chemical Building Blocks
5
How are macromolecules built
(synthesized) from subunits?
Dehydrolysis (condensation) Rxs
…And broken apart (degraded)?
Hydrolysis Rxs
Chemical Building Blocks
6
Proteins
Proteins have diverse structures;
which reflects their function
What are some of the
functions of proteins?
Enzymes!!
Molecule Transport
Gene regulation
Cell movements
Hormones
etc…
Chemical Building Blocks
7
What are the different
types of amino acids?
How are AAs similar/different
In structure?
How many AAs are there?
Chemical Building Blocks
8
How are amino acids
linked together in
proteins?
The “peptide bond”
C-terminus and N-terminus
Amino
end
Models
OH
H-
Chemical Building Blocks
Carboxyl
end
9
What are the four levels of protein structure?
 All proteins have 1O, 2O and 3O structure
-- some have 4O
What is Primary (1O) structure?
e. g., N – ALA – LYS – PHE – GLU  etc. – C
Chemical Building Blocks
10
What is Secondary (2O) structure?
α-helices & β-sheets
What is Tertiary (3O) structure?
What is Quartenary (4O) structure?
Models
Chemical Building Blocks
11
What determines and stabilizes
protein tertiary structure?
Amino acid sequence
Bonding
Hydrophobic exclusion
Chaperone proteins
Chemical Building Blocks
12
What happens if protein structure is disrupted?
Denaturation
What causes denaturation?
heat
detergents
ionic conditions
pH
Loss of function
Animation
Chemical Building Blocks
13
What are some other
characteristics of proteins?
What are …
Prosthetic groups?
e.g., HEME
Coenzymes?
-- e.g., NADH
Cofactors?
-- e.g., Mg++
What is a catalytic site?
Models
Chemical Building Blocks
14
What are the functions of carbohydrates?
Energy storage
Energy transport
Structure
Molecular Recognition
Chemical Building Blocks
15
What are the properties of …
Mono- & Disaccharides?
Oligosaccharides?
Why can oligosaccharide structure
be very complex?
Chemical Building Blocks
16
What are some important polysaccharides?
Energy storage
Starch & glycogen
Structural
cellulose & chitin
Starch and Cellulose differ
only in bonds between glucose
Starch
α-linkage
Cellulose
β-linkage
Models
Chemical Building Blocks
17
Oligosaccharides
determine blood type
ABO “antigens” are oligosaccharides
-- on lipids and proteins
Blood type reflects
type of enzyme possessed
B = galactosyl transferase
A = N-acetyl-galactosamine
transferase
AB have both
O has neither
Immune system can
respond to A or B
Chemical Building Blocks
18
What are the building blocks of DNA and RNA?
Nucleotides
ribo-nucleotides
deoxy-ribo
purines
pyrimidines
Chemical Building Blocks
19
How are nucleotides linked in a DNA strand?
Covalent bonds
within strands
3’ – 5’
Complementary
base-pairing
Hydrogen bonds
Models
Chemical Building Blocks
20
What are the functions of Lipids?
Energy storage
-- triglycerides (fats)
Membrane structure
-- phospholipids
Signaling molecules
-- steroidal hormones
Other specialized functions
What property do all lipids share?
Chemical Building Blocks
21
How does structure and function relate in:
… Phospholipids?
-- amphipathic
… Triglycerides?
-- hydrophobic
Models
Chemical Building Blocks
22
How does fatty acid saturation affect the
properties of triglycerides?
Fluidity
Metabolism
The odd history of
“Partially hydrogenated
vegetable oils”
&
“Trans-fatty acids”
Chemical Building Blocks
23